1987 Fiscal Year Final Research Report Summary
SORPTION FOR CHEMICAL SPECIATION OF TRACES OF TOXIC HEAVY METALS IN WATER
| Project/Area Number |
61550556
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
工業分析化学
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| Research Institution | NAGOYA UNIVERSITY |
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Principal Investigator |
HIRAIDE MASATAKA FACULTY OF ENGINEERING, NAGOYA UNIVERSITY, 工学部, 講師 (20111833)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Water Analysis / Chemical Speciation / Sorption / Coprecipitation-Flotation / Macroreticular Sorbents / Humic Complexes / Heavy Metals / 陸水 |
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| Research Abstract |
Traces of heavy metals may exist in fresh waters in a variety of physicochemical forms, which will exhibit different geochemical behavior and biological effects. Metal-humic and -fulvic acid complexes are among the typical and important species, whose determination requires preconcentration. In the present work, a macroreticular nonionic resin Amberlite XAD-2 is pulverized and treated with indium ions to saturate its cation-exchangeable sites. Inorganic cations and anions, EDTA complexes and colloidal hydrated metal oxides are not retained on the column at all. The humic complexes sorbed on the column are ultrasonically desorbed with nitric aicd and determined by graphite-furnace atomic absorption spectrometry.
A coprecipitation-flotation technique is applied to the preconcentration of humic acid at the g/1 level. Humic acid is coprecipitated with iron(III) hydroxide and floated to the solution surface with anionic surfactants and nitrogen bubbles. The precipitate is separated and dissolved in hydrochloric acid. The acid-insoluble humic acid is filtered off on an ultrafilter and dissolved in an alkaline solution for measurements of absorption spectra, molecular weight distribution and complexing ability. Further, chemical species of iron in fresh waters were examined in detail by using synthetic water samples.
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